Move optparse code out of run_uh and into own file
Get rid of manpage.xml and its generation routine

Outdated, and there's no need for xslt to assemble these pieces.
Add custom options formatter for manpage generation

Simply running `options.py` should now generate unknown-horizons.6.
Track generated manpage in content/packages/

Generation: ./options.py > content/packages/unknown-horizons.6
Merge pull request #2173 from unknown-horizons/manpage

Manpage updates